我的java代码有问题。
我想做一个画家程序，但每当我选择一个形状并绘制它时
之前绘制的所有形状都变得与此形状相同。这是代码。
我知道问题出在 paintComponent 中的 for 语句，但我可以用什么替换它？
class inner extends JPanel implements MouseListener,MouseMotionListener{
private int oldx,oldy,newx,newy;
private Point point1,point2;
private Shape newRec,line1;
Rectangle currRec;
private Vector shape;
private boolean status,status1;
private int count=0;
private Object line;
inner(){
point1=point2=new Point(0,0);
shape = new Vector();
addMouseListener(this);
addMouseMotionListener(this);
}
public void mouseDragged(MouseEvent event) {
point2=event.getPoint();
newx = point2.x;
newy = point2.y;
if(Universal==7){
line = new Object(oldx,oldy,newx,newy);
status = true;
repaint();
}
currRec = new Rectangle(Math.min(point1.x,point2.x),Math.min(point1.y,point2.y),Math.abs(point1.x-point2.x),Math.abs(point1.y-point2.y));
status = true;
repaint();
}
@Override
public void mouseMoved(MouseEvent arg0) {}
public void mouseClicked(MouseEvent arg0) {}
public void mouseEntered(MouseEvent arg0) {}
@Override
public void mouseExited(MouseEvent arg0) {}
public void mousePressed(MouseEvent event) {
point1=event.getPoint();
oldx=event.getX();
oldy=event.getY();
}
@Override
public void mouseReleased(MouseEvent event) {
point2=event.getPoint();
newx=event.getX();
newy=event.getY();
//count++;
if(Universal==7){
line1 = new Shape(point1.x,point1.y,point2.x,point2.y);
shape.add(line1);
//Graphics g = getGraphics();
//g.setColor(colour);
//g.drawLine(point1.x,point1.y,point2.x,point2.y);
count++;
repaint();
}
else if(Universal==1||Universal==2||Universal==3||Universal==4||Universal==5||Universal==6){
newRec = new Shape(Math.min(point1.x,point2.x),Math.min(point1.y,point2.y),Math.abs(point1.x-point2.x),Math.abs(point1.y-point2.y));
shape.add(newRec);
count++;
repaint();
}
}
///// the problem is in here
public void paintComponent(Graphics g){
super.paintComponent(g);
Shape c;
g.setColor(colour);
for(int i=0;i<shape.size();i++){
c = (Shape) shape.get(i);
if(Universal==1){
g.drawRect(c.x, c.y, c.w, c.h);
if(status){
g.drawRect(currRec.x, currRec.y, currRec.width, currRec.height);
}
}
if(Universal==2){
g.fillRect(c.x, c.y, c.w, c.h);
if(status){
g.fillRect(currRec.x, currRec.y, currRec.width, currRec.height);
}
}
if(Universal==3){
g.drawRoundRect(c.x, c.y, c.w, c.h, c.w/4, c.h/4);
if(status){
g.drawRoundRect(currRec.x, currRec.y, currRec.width, currRec.height,currRec.width/4,currRec.height/4);
}
}
if(Universal==4){
g.fillRoundRect(c.x, c.y, c.w, c.h, c.w/4, c.h/4);
if(status){
g.fillRoundRect(currRec.x, currRec.y, currRec.width, currRec.height,currRec.width/4,currRec.height/4);
}
}
if(Universal==5){
g.drawOval(c.x, c.y, c.w, c.h);
if(status){
g.drawOval(currRec.x, currRec.y, currRec.width, currRec.height);
}
}
if(Universal==6){
g.fillOval(c.x, c.y, c.w, c.h);
if(status){
g.fillOval(currRec.x, currRec.y, currRec.width, currRec.height);
}
}
if(Universal==7){
g.drawLine(c.x, c.y, c.w, c.h);
if(status){
g.drawLine(line1.x, line1.y, line1.w,line1.h);
}
}
if(Universal==8){
shape.clear();
}
}
}
最佳答案
Universal 只会在任何给定时间成为给定值。
油漆不是累积性的，而是具有破坏性的。
也就是说，每次调用 paintComponent 时，所有以前的内容都会被删除/删除干净，并且您需要“重新绘制”内容。
您不应依赖单个标志，而应将 Shape 添加到某种 List 中，并在 paintComponent 时重新绘制它们。叫做。同样，您可以简单地将“类型”(int) 添加到 List 并在每次重绘时处理该列表
看看Painting in AWT in Swing油漆过程的解释
关于Java Paint 程序绘制形状，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/16426823/